Paediatric Neurology Flashcards
Inheritance pattern of Duchenne Muscular Dystrophy
X-linked
At what age do symptoms of Duchenne muscular dystrophy typically develop
1-3 years
Prognosis of Duchenne muscular dystrophy
May experience some improvement 3-6y
Gradual relentless deterioration
Usually wheelchair bound by 8-12y
Most die in late teens/twenties with pulmonary complications
Cause of disease in Duchenne muscular dystrophy
Defect in the dystrophin gene leading to total deficiency of the dystrophin protein (involved in myocyte cytoskeleton formation)
Leads to deterioration and break down of muscle
Signs of Duchenne muscular dystrophy
Delayed walking (first steps typically at 18m)
Frequent falls
Difficulty climbing stairs, running, jumping
Muscle weakness (proximal before distal)
Waddling gait
Toe-walking + protruded abdomen + lordosis
Calf pseudohypertrophy
Gower’s sign
Normal sensation
Hyporeflexia or areflexia
What is Gower’s sign
Children with DMD while on floor using hands to “walk up” legs until standing again
Diagnosis of DMD
CK levels 50-100 times higher than normal
DNA studies
+/- electromyography
+/- muscle biopsy (no dystrophin)
Treatment of Duchenne muscular dystrophy
Glucocorticoids after 5y Symptom management: - Immunisations (incl. annual fluvax) - Cardiac surveillance - Pulmonary function
Definition of Cerebral palsy
a group of non-progressive clinical syndromes that are characterised by motor and postural dysfunction due to abnormalities of the developing brain resulting from a variety of causes
Prevalence of cerebral palsy
2 per 1000
Risk factors for cerebral palsy
Prematurity Low birth weight Heavy maternal alcohol consumption Maternal smoking Infections during pregnancy
Potential causes of cerebral palsy
Prematurity Intrauterine growth restriction Intrauterine infection Antepartum haemorrhage Severe placental pathology Multiple pregnancy
Classifications of cerebral palsy
Spastic (70%)
Dyskinetic (10-15%_
Dystonic, Athetosis, Chorea
Ataxic (
Early signs of Cerebral palsy
Poor feeding in neonatal period
Irritability, poor sleep, difficult to handle/cuddle
Frequent vomiting
Persistent primitive reflexes
Abnormal tone (increased, decreased or normal) may cause signs such as persistent asymmetric fisting, tongue retraction and thrust, tonic bite etc.
Poor head control
Delayed motor development
Signs of spastic type cerebral palsy
Hypertonia Clonus Hyperreflexia Extensor plantar responses Impaired fine motor movement Difficulty in isolating individual movements Slow effortful voluntary movements Contractures often develop Signs may be isolated to legs only, or to only one side of the body
Signs of dyskinetic type cerebral palsy
More than one form of involuntary movement
Variable dysarthria, motor and intellectual disability
Chorea (rapid irregular contractions)
Athetosis (slow, smooth, writhing movements of distal muscles)
Persistence of primitive muscles
Dystonia
Signs of ataxic type cerebral palsy
Motor and language milestones delayed
Ataxia usually improves with time
Speech is typically slow, jerky and explosive
Diagnosis of cerebral palsy
Clinical diagnosis made in the first 2 years of life based on a combination of the following key features:
- abnormal motor development and posture
- motor impairment is permanent and non-progressive
- motor impairment is attributed to an insult that occurred in the developing foetal or infant brain
- motor impairment results in limitations in functional abilities and activity
- motor impairment is often accompanied by secondary musculoskeletal problems, epilepsy, and/or disturbances of sensation, perception, cognition, communication and behaviour
Differences in presentation of paediatric migraines v adult
Often bilateral
Photophobia and phonophobia often do not develop until 12y
Abdominal migraine type (recurrent abdominal pain with no identifiable cause)
Management of acute migraine in child
NSAIDs or paracetamol
Preventative medications most recommended for paediatric migraines
Topiramate
Amitriptyline
Propanolol
Antiserotonergics (cyproheptadine)
Lifestyle modifications to reduce paediatric migraine frequency
Hydration
Sleep hygiene
Exercise
Meals TDS (avoid hunger)
Presentation of breath holding attacks
More common in preschool children (peak at 2y)
Often after child upset after being scolded
Sometimes follows minor injury or fall
Child screams, after period of forced expiration becomes apnoeic and loses consciousness
Child returns to normal after few seconds
May precipitate in generalised tonic clonic jerking or opisthotonus
Definition of opisthotonus
Spasm of muscles causing backward arching of the head, neck and spine
Management of breath holding attacks
No treatment required
Reassure parents
CSF findings in cryptococcal meningitis
Reduced glucose
Predominantly lymphocytic picture
CSF findings in tuberculous meningitis
EARLY DISEASE:
reduced glucose with predominant polymorphonuclear cells
LATE DISEASE:
Reduced glucose with predominant lymphocytes
Result of radial nerve injury
Wrist drop
Sensory loss of the anatomical snuffbox and first dorsal webspace
Result of median nerve injury
Loss of sensation over the thumb, index middle and lateral half of the ring finger
Result of ulnar nerve injury
Claw hand deformity and loss of sensation over medial half of the ring finger and little finger
Causes of seizures based on age of onset
First 1-2 years: - febrile convulsions - birth asphyxia - Congenital abnormalities School Age - Idiopathic - ?Genetic Adults: - Tumours - stroke - Injury
Definition of neonatal seizure
Paroxysmal EEG activity often with motor manifestations including effects on respiration, heart rate and blood pressure occurring in first 28 days of life
Incidence of neonatal seizures
2-4/1000 live term births
10-130/1000 live preterm births
Causes of neonatal seizures
Hypoxic-ischaemic encephalopathy (HIE)
- most common cause in term infants (40-60%)
- present within first 24 hours
- most common cause for babies with poor long term prognosis
INTRACRANIAL HAEMORRHAGE
(intraventricular, intracerevral, subdural, subarachnoid)
CNS INFECTION
- meningitis (viral or bacterial)
- Encephalitis
- Intrauterine TORCH infections
- Most commonly GBS, E coli, listeria, staph
PERINATAL STROKE
METABOLIC (BGL, Ca, Mg, Na, pyridoxine)
DRUG WITHDRAWAL
CONGENITAL (chromosomal, congenital brain anomalies, neuro-degenerative)
BENIGN IDIOPATHIC NEONATAL CONVULSIONS
- multifocal clonic seizures day 5, cease within 15 days
BENIGN FAMILIAL NEONATAL CONVULSIONS
- tonic or clonic seizures on day 2-3, cease after few weeks, good prognosis
Differentiating neonatal seizure from jitteriness
Jitteriness: provoked by stimulus, predominanly rapid, oscillatory movements/tremor. Movements cease when limb is held. Conscious state awake or asleep, not altered during episode. No eye deviation
Seizure: not provoked by stimulus, clonic/tonic movements which do not cease when limb is held. Altered conscious state, eye deviation
Clinical classifications of neonatal seizures
CLONIC (50%): more common in term babies, focal may suggest underlying focal neuropathy
TONIC (20%): more common in preterm babies, typically extension of limbs with opisthotonic posturing
SUBTLE (10-25%): Eyes (staring/blinking/deviation), Oral (lip smacking, mouthing, chewing, sucking, tongue thrusting) Limb (boxing, swimming, pedalling) Autonomic (apnoea, tachycardia, unstable BP) More common in term babies, occur in babies with severe global insult (e.g. IV haemorrhage)
MYOCLONIC (5%): seeing in drug withdrawal, esp opiates. Rapid isolated jerks
Investigations to perform in neonatal seizures
BGL Serum electrolytes, INCLUDING CALCIUM AND MAGNESIUM Serum ammonia CBE Blood cultures ABG Serum amino acids Urine amino acids and organic acids Thrombophilia screen (if has suffered a stroke) Lumbar puncture Cranial USS EEG
Anticonvulsant therapy in neonatal seizures
Should be considered to treat seizures AFTER cause specific treatment when:
- prolonged (more than 2-3 minutes)
- Frequent (more than 2-3 per hour)
- disruption of ventilation and/or BP
Administer IV for rapid onset
Most commonly used:
- phenobarbitone, phenytoin, midazolam, Clonazepam, lignocaine
Definition of febrile convulsions
Convulsions in a child between 6m and 6y of age, in the setting of an acute febrile illness without previous afebrile seizures, significant prior neurological abnormality, and no CNS infection
Simple v complex febrile convulsions
Simple: generalised lasting less than 5 minutes and not recurring during a 14 hour period
Complex: focal, prolonged more than 5 minutes or multiple within the first 24 hours
Recurrence of febrile convulsions
recur in 1/3 of children during early childhood
Risk of future epilepsy only slightly higher than general population (1-2% overall risk)
Higher risk of recurrence or afebrile convulsions if experience complex febrile convulsions
Peak incidence of febrile convulsions
12-18m
Risk factors for febrile convulsions
Age (12-18m) High fever Infection - particularly viral (HHV-6, influenza, parainfluenza, adenovirus) Immunisation (increased risk after administration of DTP and MMR vaccines) Genetic susceptibility Prenatal nicotine exposure Iron deficiency Allergic rhinitis
Clinical presentation of febrile convulsions
Occur on first day of illness in majority of children
Fever commonly above 39
Most commonly generalised clonic (unless complex - focal onset)
Febrile status epilepticus: continuous seizures or intermittent seizures without neurologic recovery lasting for over 30 minutes
Clinical diagnostic criteria for a febrile convulsion
- A convulsion associated with temperature greater than 38
- Child older than 3m and younger than 6y
- Absence of CNS infection or inflammation
- Absence of acute systemic metabolic abnormality that may produce convulsions
- No history of afebrile seizures
Management of febrile convulsions
Emergency rescue therapy (if continuing for more than 5 minutes)
- Midazolam buccally or intranasally
OR
- diazepam rectally
OR
- Lorazepam IV, oral or IM
For ongoing seizures: phenytoin or phenobarbitone
Admission to hospital not usually required
Risk factors for recurrence of febrile convulsiosn
Overall recurrence rate 30%
Age at first seizure less than 1y (50-65%)
History of febrile seizures in first degree relative
Low degree of fever while in the emergency department
Brief duration between onset of fever and initial seizure
Abnormal development before the first febrile seizure
Recurrence of seizures within the same illness
Number of subsequent febrile illnesses
Unprovoked seizure after a febrile seizure
Primary v secondary epilepsy in childhood
Idiopathic/Primary 60%
Secondary: 40%
Common causes - congenital brain defects, trauma, birth asphyxia, infections (congenital or post natal)
Less common: tumours, metabolic conditions, familial neurodegenerative (e.g. Tay-Sach’s), neurocutaneous syndrome (tuberculous sclerosis)
Types of generalised seizures
Absence seizures (clusters of 5-10 sec staring, impaired consciousness) Generalised tonic-clonic Clonic seizures (rhythmical muscle contractions usually involving arms neck and face) Myoclonic seizures (sudden brief muscle contractions alone or in clusters, typically of arms, no impaired consciousness) Tonic seizures (sudden muscle stiffening +/- impaired consciousness and falling to ground) Atonic seizures (drop seizures - sudden loss of control of muscles esp legs - collapsing to ground)
Seizure syndromes
Benign familial infantile epilepsy Infantile spasms/West's syndrome Myoclonic epilepsy of infancy Lennox-Gastaut Syndrome Landau-Kleffner Syndrome Benign Rolandic Epilepsy Juvenile myoclonic epilepsy Rasmussen's syndrome Frontal lobe epilepsy Temporal lobe epilepsy Reflex epilepsies
Benign familial infantile epilepsy
Autosomal dominant epilepsy syndrome
Afebrile seizures in otherwise normal infant
Begins 6m, lessens by 3y
Infantile spasms/West’s syndrome presentation
Sudden jerk followed by stiffening (jack-knife seizures) - arms flung out as knees are pulled up and body bends forward Last 1-2 sec Occur in a series Occur most commonly just after waking Begin at 3-12m, stop by 4y
Management of West’s syndrome/infantile spasms
Steroid therapy and vigabatrin
Prognosis of infantile spasms
60% have brain injury before the seizures begin
Most will be developmentally delayed later in life
Many develop other kinds of epilepsy
Associated with primary causes e.g. tuberous sclerosis, PKU
Myoclonic epilesy of infancy
Myoclonic seizures beginning in 1st year of life
Can be accompanied by other seizure types
Benign or severe (psychomotor retardation, speech delay, ataxia)
Severe form = Dravet syndrome - mortality in early life 10%
Lennox-Gastaut syndrome
Epilepsy syndrome onset 3-7y old
Multiple seizure types (tonic and atonic mainly)
Mental retardation and other neurological abnormalities, psychotic symptoms common, neurodevelopment often normal before first seizure
Intellectual and behavioural abnormalities
CBZ can precipitate attacks
Management of Lennox Gastaut syndrome
Seizures are difficult to control and need life-long treatment
Valproate, lamotrigine, topiramate etc. may be useful
Landau-Kleffner Syndrome
Deterioration of higher cortical functioning (language) on basis of frequent epileptiform activity
Develop normally until 3-6y
Present initially with auditory verbal agnosia (child behaves as if deaf)
Acquired expressive aphasia
Personality disorders
Seizures typically occur during sleep
EEG abnormalities: bilaterral centerotemporal spikes and sharp waves that spread widely through both hemispheres
Benign rolandic epilepsy
Simple partial seizures Twitching, numbness or tingling of child's face or tongue last less than 2 minutes 15% of all chilhood epilepsies begins 6-8y Usually occur at night, may be infrequent Many children do not need medications Usually self-limiting by 15y
Juvenile myoclonic epilepsy
Healthy young teenager
- myoclonic jerks
- absence seizures often precede other types of seizures OR
- generalised tonic-clonic seizures (tendency to occur upon awakening)
Differentials for seizures
Shuddering attacks Breath-holding spells Self-gratification behaviour Cardiogenic syncope GORD (change in posture, colour etc.) Migraine auras Sleep disorders
Spina bifida definition
AKA myelomeningocele:
The most common neural tube defect and the most severe birth defect that is compatible with live, characterised by a cleft in the vertebral column with a corresponding defect in the skin so that the meninges and spinal cord are exposed
Incidence of spina bifida
3/10,000 live births
Risk factors for spina bifida
Folic acid deficiency
Administration of folic acid antagonists during pregnancy (CBZ, phenytoin, valproate, trimethoprim, MTX)
Prenatal diagnosis of spina bifida
Increased serum maternal AFP
Diagnosis confirmed by USS
- less than 12w GA - irregularities of bony spine/bulging within posterior contour of foetal back
- greater than 12w GA Lemon sign (concave shape of frontal calvarium) or banana signs (posterior convexity of cerebellum)
Post-natal diagnosis of spinabifida
Neural plate visible (raw, red, fleshy plaque seen through a defect in the vertebral column and the skin)
Membranous sac protruding through defect containing meninges CSF and nerve roots
Management of spina bifida
If diagnosed prenatally: delivery at tertiary hospital, serial USS and deliver early if indication of rapidly increasing ventriculomegaly
Management of neonate:
Cover defect with sterile saline-soaked dressing, +/- plastic wrap if large
Prone or lateral position to avoid pressure on lesion
Thorough neurological exam (findings often improve in first 72h, aim to define baseline)
Assess for other congenital anomalies
Prophylactic broad spectrum ABx until the back is closed
Surgical closure within first 72 hours - monitor for hydrocephalus
